The Doping Effect of Bi on TiO2 for Photocatalytic Hydrogen Generation and Photodecolorization of Rhodamine B

The dependence of photoactivity on Bi doping on TiO2 was studied for photocatalytic hydrogen generation and rhodamine B (RhB) decolorization. After Bi doping, the hydrogen photogeneration rate increased by a factor of ca. 10, and the decolorization rate for RhB increased two times under visible light radiation (>420 nm). The doping also led to the remarkable photocurrent enhancement. The clear dependence between photocurrent intensity and photoactivity was observed. The optimal dosage of Bi in TiO2 was about 1.0 mol %. The Bi species existed both in Bi2O3 and Bi-0 forms in TiO2, and the ratio of Bi2O3 and Bi-0 was dependent on the treatment processes. Results implied that Bi doping increased photoinduced charge separation and resulted in a relatively lower overpotential for H-2 photoevolution.